The prototype Corsair was built in response to a U.S. Navy design competition of February 1938. Chance Vought built their candidate around the Pratt & Whitney XR-2800-2 Wasp radial air-cooled engine, capable of providing 1,800 hp (in comparison the Bf 109E, in develop in 1938, had a 1,175 hp engine). This powerful engine really needed a large propeller – the model eventually used was a thirteen foot three blade Hamilton Standard propeller. With normal straight wings, this would have resulted in abnormally tall landing gear. The designer’s solution to this was to use the inverted gull wing, which by lowering the bottom of the wings allowed the use of more normal landing gear.
The prototype aircraft was armed with two .30 calibre machine guns in the nose and one .50 calibre machine guns in each outer wing panel. Those wing panels could fold up for carrier use. The wings could also each carry twenty small 5.2 pound anti-aircraft bombs to be used against enemy bombers.
The prototype first flew on 29 May 1940. It was immediately obvious that the aircraft was fast – it would soon become the first single seater fighter to reach 400 mph in level flight (earlier aircraft had reached that speed in a dive). This made it 50 mph faster than the Bf 109E. Cruising speed was 180 mph. It was also highly manoeuvrable. However, there were some problems with the aircraft. The “birdcage” cockpit canopy was too restrictive, and visibility was poor. More seriously, the aircraft was difficult to land – the port wing tended to drop at low speed, and it bounced on landing, not acceptable behaviour in a carrier aircraft. Despite these flaws, the high performance of the Corsair was obvious, and after tests in October 1940 the Navy placed an order for a production version.
The aircraft the Vought delivered was significantly different from the prototype. The cockpit was moved back three feet. This allowed the fuel tanks to be removed from the wings and placed in front of the pilot. This in turn allowed the installation of three .50 calibre machine guns in the each wings. The cockpit canopy was slightly improved, giving more space for the pilot to move. The under wing anti-aircraft bombs were replaced by two small bomb racks for normal bombs. Finally, the engine was changed to the Pratt & Whitney XR-2800-8, giving 2,000 hp. The top speed rose to 425 mph. These changes did delay the production of the aircraft, but made it a much more potent fighter.
The Navy ordered 584 Corsairs. However, when the production aircraft arrived the Navy decided that it was not safe for carrier operations. In addition to the problems in the prototype, the new cockpit position reduced visibility when landing. Accordingly, the first Corsairs were allocated to the Marines and to land based Navy squadrons.
The Royal Navy also received a large number of Corsairs, and almost immediately began operation them from carriers. The Corsair was first used in action from a carrier on 2 April 1944, when aircraft based on HMS Victorious took part in an attack on the German battleship Tirpitz. The British had a couple of advantages when using the early Corsair from carriers. The first was that accident – the aircraft hangers in the British carriers were not as tall as those in American ships, and so eight inches had to be chopped off the wings of the Corsair. One side-effect of this was to make the aircraft easier to handle in a stall, and thus easier to land on a carrier. More significant was that British carriers such as the Victorious had armoured flight decks. This eliminated one major problem with the Corsair on American carriers – it was eventually discovered that the arrestor hook was acting as an axe, cutting its way through their wooden flight decks.
This was not an official designation, but is now often used to describe late production F4U-1s. These aircraft replaced the “birdcage” canopy with a much cleaner blown-hood canopy. In addition, the pilot’s seat was raised by 9 inches, improving the view over the long nose and making deflection shooting rather easier. A side-effect of this change was that the pilot was almost standing – the rudder pedals were only raised by half an inch. The majority of wartime Corsairs had no cockpit floor (partly because the original design had included a window in the base of the fuselage to allow the pilot to aim the anti-aircraft bombs) so the new posture could make some pilots slightly nervous.
The F4U-1 and 1A were also produced by Goodyear as the FG-1 and by Brewster as the F3A-1. Goodyear eventually produced nearly as many of the dash one Corsairs as Vought. Brewster never achieved the same success, and their aircraft were most often used in training establishments. The three manufacturers produced aircraft that were almost, but not quite, identical, often requiring slightly different spare parts.
The F4U-1C was produced at the same time as the 1D. The main difference between the models was that the 1C carried two 20mm cannon in each wing instead of the six machine guns. The 1C and 1D used an improved blown canopy, with two more struts removed, further improving the view. Only 200 of this variant were produced. It entered combat in Spring 1945.
The F4U-1D was the first version of the Corsair to serve on-board U.S. carriers. By now Vought had managed to correct the bounce and the dip to port at slow speeds. The first units moved on-board in December 1944, and the Corsair quickly replaced the Grumman F6F Hellcat as the fighter of choice for carrier operations.
The 1D used the Pratt & Whitney R-2800-8W engine. The W signifies that this engine was equipped with a water-methanol injection system, allowing the pilot to boost horsepower for a short period.
The 1D carried the standard six-gun wing armament. In addition it was given an increased capacity to act as a fighter-bomber. Four rocker launch stubs were fitted to each wing, allowing the aircraft to carry eight five inch HVAR rockets. The wing-root bomb racks were altered to allow the Corsair to carry two 1,000 lb bombs or two 154 gallon drop tanks (or one of each). The 1D entered combat in the spring of 1944 with ground based squadrons. It was also produced by Goodyear as the FG-1D.
Introduction - F4U-1 - F4U-2 - XF4U-3 - F4U-4 - F4U-5 - AU-1 - F4U-7 - American Service - British Service - Statistics